Fix blocked website access and add troubleshooting page

extension/host-access.js

@@ -0,0 +1,88 @@
+export const HOST_ACCESS_REQUIRED_STATUS = 'host_permission_required';
+
+export function normalizeTabId(value) {
+    if (value === null || value === undefined || value === '') return null;
+    const tabId = Number(value);
+    return Number.isInteger(tabId) && tabId > 0 ? tabId : null;
+}
+
+export function describeTabUrl(rawUrl) {
+    if (typeof rawUrl !== 'string' || !rawUrl) return null;
+
+    try {
+        const url = new URL(rawUrl);
+        if (url.protocol === 'http:' || url.protocol === 'https:') {
+            return {
+                url: rawUrl,
+                host: url.host,
+                originPattern: `${url.origin}/*`
+            };
+        }
+        if (url.protocol === 'file:') {
+            return {
+                url: rawUrl,
+                host: 'local file',
+                originPattern: 'file:///*'
+            };
+        }
+    } catch (_e) {
+        // Invalid and browser-internal URLs cannot receive host access.
+    }
+
+    return null;
+}
+
+export async function inspectTabHostAccess(chromeApi, tabId) {
+    const tab = await chromeApi.tabs.get(tabId);
+    const descriptor = describeTabUrl(tab?.url || '');
+    if (!descriptor) {
+        return {
+            tab,
+            url: tab?.url || '',
+            host: null,
+            originPattern: null,
+            granted: null
+        };
+    }
+
+    if (typeof chromeApi.permissions?.contains !== 'function') {
+        return { tab, ...descriptor, granted: null };
+    }
+
+    try {
+        const granted = await chromeApi.permissions.contains({
+            origins: [descriptor.originPattern]
+        });
+        return { tab, ...descriptor, granted: granted === true };
+    } catch (_e) {
+        // Permission inspection is advisory. The actual script injection below
+        // remains the source of truth, including temporary activeTab access.
+        return { tab, ...descriptor, granted: null };
+    }
+}
+
+export async function addTabHostAccessRequest(chromeApi, tabId) {
+    if (typeof chromeApi.permissions?.addHostAccessRequest !== 'function') {
+        return false;
+    }
+
+    try {
+        await chromeApi.permissions.addHostAccessRequest({ tabId });
+        return true;
+    } catch (_e) {
+        return false;
+    }
+}
+
+export async function removeTabHostAccessRequest(chromeApi, tabId) {
+    if (typeof chromeApi.permissions?.removeHostAccessRequest !== 'function') {
+        return false;
+    }
+
+    try {
+        await chromeApi.permissions.removeHostAccessRequest({ tabId });
+        return true;
+    } catch (_e) {
+        return false;
+    }
+}